Preparation Of Pyraclostrobinl·Flubeneteram 17% SC And Its Field Control Effect On Tomato Botrytis Cinerea

Pyraclostrobin,a highly effective methoxyacrylate fungicide,not only has high bactericidal activity but also has the stimulating and inducing effect that can adjust the physiological function of plants.Flubeneteram are SDHI fungicides independently developed in China.The development and utilization of this kind of fungicide has always been a research hotspot and has broad market prospects.In this study,the two agents were mixed to determine the optimal ratio,and qualified suspension agents were processed through the screening of auxiliary agents,so as to provide theoretical basis and technical support for improving the control effect of the agents on Botrytis cinerea,delaying the emergence of drug resistance,reducing the use amount of pesticides and prolonging the service life of the two agents.For this reason,this research has carried on the research from the following aspects.1.The mycelial growth rate method was used to determine the EC50 of two kinds of agents,Pyraclostrobin and Flubeneteram against B.cinerea,respectively.The results show that the EC₅₀of Pyraclostrobin was 0.78 mg/L,the EC₅₀of Flubeneteram was 0.58 mg/L.After that,the interaction method was used to preliminarily screen out the concentration ratio of 4:6 with higher toxicity level of the two chemicals,and further accurately found out the highest concentration ratio of 8:9 and SR value of 6.039.2.According to the synergistic effect,the two kinds of agents were compounded and processed into suspension agent.Through the determination of convection point value and a large number of experimental comparison,the types or dosage of different wetting dispersant,thickener,antifreeze,defoamer and preservative were screened,and the final formula was determined as follows:8%pyrazolyl fungicide,9%chlorophenyl ether amide,zbs-190sulfonate 2%,zbs-105 carboxylate 4%,magnesium aluminum silicate 1%,xanthan gum0.2%,sodium benzoate 0.2%,organic silicon 0.2%,ethylene glycol 5%,deionized water make up to 100%.3.Based on the characteristics and basic requirements of suspension agent,the quality control standard of Pyraclostrobinl·Flubeneteram 17%SC suspension agent was established.The content of effective components was detected by HPLC,and the p H value,suspension rate,lasting foaming,dumping and other indicators were detected by national standard.All test items are qualified.4.The fungicides of Pyraclostrobinl·Flubeneteram 17%SC,two single fungicides and common fungicides in the market were used to control B.cinerea in the field.The results showed that the control effect of the mixture was higher than that of the two single fungicides at the same concentration.The control effect of leaf reached 85.90%and 80.92%,and that of fruit reached 79.48%and 77.00%,which was much higher than that of pyrimethanil and procymidone.It is environmentally friendly and suitable for market development.